The most ancient shape of the episcopal staff is found represented in the catacombs; a short handle, with a plain boss or oval knob bent aside at the top like the pagan _lituus_. Sometimes in the catacombs we also find the truer form of a shepherd’s crook, a plain but complete curve at the extremity. The Tau is commonly seen and given without apparent distinction to bishops and abbots in manuscripts of the eighth and ninth centuries, about which period there came in another fashion, unpleasing and hardly intelligible in its design, where the crook is but slightly bent and extended almost horizontally from the staff itself. One more shape, and more rare, was a double plain crook like horns joined together. After all these came the admirable design, of which the South Kensington museum possesses one or two splendid examples, wherein the volute is carried half round again and frequently contains within the circle other ornaments or groups of figures. [Illustration: IVORY CARVING, HEAD OF A TAU OR T SHAPED STAFF, IN WALRUS TUSK, THE COMPARTMENTS CONTAINING THE SIGNS OF THE ZODIAC. 12^{th} CENT (SOLTIKOFF COLL) L, 5 IN S. K. M. (N^o 215 ’65) F. A. SLOCOMBE FECIT] The extremities of the Taus were often hollowed, to receive relics. The beautiful Tau now at Kensington, engraved in the etching, shows the old recesses; but the crystal ends are lost. It is of this Tau that a learned author writes as follows, in the Mélanges archéologiques:—“Avant de quitter ce beau monument, je ferai observer la riche ciselure du treillis séparant les signes. Il est à peine croyable que chaque petite perle d’ivoire le long des entrelacs enchâsse une pierre précieuse, et que les yeux des animaux sont ainsi formés.” A very fine ivory of the same admirable kind and style is preserved in the library at Rouen, probably of earlier date, of the tenth century; and another is in the Cluny museum, unusually simple in shape and plain in ornament, which was found at St. Germain-des-Prés in the tomb of Morard, abbot of that monastery from 990 to 1014. In the etching is another Tau, also at Kensington. Ivory Taus are of great rarity. They were gradually superseded towards the end of the twelfth century by that form which, with certain varieties of ornament, has continued down to our own times. The most common mode of treating the volute itself was to imitate a serpent; and the termination of the crook was the head of the serpent, sometimes with widely-expanded jaws.